Methods and apparatus for providing an integrated multi-hop routing and cooperative diversity system

ABSTRACT

Embodiments of methods and apparatus for providing an integrated multi-hop routing and cooperative diversity system are generally described herein. Other embodiments may be described and claimed.

CROSS REFERENCE TO RELATED APPLICATION

The present application is a continuation of U.S. patent applicationSer. No. 11/206,494, filed Aug. 17, 2005, entitled “METHODS ANDAPPARATUS FOR PROVIDING AN INTEGRATED MULTI-HOP ROUTING AND COOPERATIVEDIVERSITY SYSTEM,” the entire disclosure of which is hereby incorporatedby reference.

TECHNICAL FIELD

The present disclosure relates generally to wireless communicationsystems, and more particularly, to methods and apparatus for providingan integrated multi-hop routing and cooperative diversity system.

BACKGROUND

As wireless communication becomes more and more popular at offices,homes, schools, etc., the demand for resources may cause networkcongestions and slowdowns. To reduce performance degradations and/oroverload conditions, a wireless mesh network may be implemented in awireless communication system. In particular, a wireless mesh networkmay include two or more nodes. If one node fails to operate properly,the remaining nodes of a wireless mesh network may still be able tocommunicate with each other either directly or through one or moreintermediate nodes. Accordingly, a wireless mesh network may providemultiple paths for a transmission to propagate from the source to thedestination. Thus, a wireless mesh network may be a reliable solution tosupport the increasing demand for wireless communication services.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram representation of an example wirelesscommunication system according to an embodiment of the methods andapparatus disclosed herein.

FIG. 2 depicts an example wireless mesh network operating in accordancewith a multi-hop routing protocol.

FIG. 3 is a block diagram representation of an example routing table ofa communication node associated with the example wireless mesh networkof FIG. 2.

FIG. 4 depicts an example wireless mesh network operating in accordancewith a cooperative diversity protocol.

FIG. 5 is a block diagram representation of an example cooperation tableof a communication node associated with the example wireless meshnetwork of FIG. 4.

FIG. 6 is a block diagram representation of an example communicationnode.

FIG. 7 is a block diagram representation of an example protocol stackassociated with the example communication node of FIG. 6.

FIG. 8 depicts an example integrated multi-hop routing and cooperativediversity system.

FIG. 9 is a block diagram representation of an example routing table ofthe example communication node of FIG. 6.

FIG. 10 is a block diagram representation of an example cooperationtable of the example communication node of FIG. 6.

FIG. 11 is a flow diagram representation of one manner in which theexample communication node of FIG. 6 may be configured to provide anintegrated multi-hop routing and cooperative diversity system.

FIG. 12 is a block diagram representation of an example processor systemthat may be used to implement the example communication node of FIG. 6.

DETAILED DESCRIPTION

In general, methods and apparatus for providing an integrated multi-hoprouting and cooperative diversity system are described herein. Themethods and apparatus described herein are not limited in this regard.

Referring to FIG. 1, an example wireless communication system 100including a wireless mesh network 110 is described herein. In oneexample, the wireless mesh network 110 may be an extended service set(ESS) mesh network based on developments by the Institute of Electricaland Electronic Engineers (IEEE). The wireless mesh network 110 mayinclude a plurality of mesh nodes 120, generally shown as 121, 122, 123,124, and 125. Although FIG. 1 depicts five mesh nodes, the wireless meshnetwork 110 may include additional or fewer mesh nodes.

As described in detail below, the plurality of mesh nodes 120 mayinclude access points, redistribution points, end points, and/or othersuitable connection points for traffic flows via mesh paths havingmultiple hops. One or more of the plurality of mesh nodes 120 may alsobe operatively coupled to a common public or private network such as theInternet, a telephone network, a local area network (LAN), a cablenetwork, and/or another wireless network via connection to an Ethernet,a digital subscriber line (DSL), a telephone line, a coaxial cable,and/or any wireless connection, etc. Accordingly, the wireless meshnetwork 110 may be implemented to provide a wireless personal areanetwork (WPAN), a wireless local area network (WLAN), a wirelessmetropolitan area network (WMAN), a wireless wide area network (WWAN),and/or other suitable wireless communication networks.

The plurality of mesh nodes 120 may use a variety of modulationtechniques such as spread spectrum modulation (e.g., direct sequencecode division multiple access (DS-CDMA) and/or frequency hopping codedivision multiple access (FH-CDMA)), time-division multiplexing (TDM)modulation, frequency-division multiplexing (FDM) modulation, orthogonalfrequency-division multiplexing (OFDM) modulation, multi-carriermodulation (MDM), and/or other suitable modulation techniques tocommunicate via wireless links. In one example, one or more of theplurality of mesh nodes 120 may implement OFDM modulation to transmitlarge amounts of digital data by splitting a radio frequency signal intomultiple small sub-signals, which in turn, are transmittedsimultaneously at different frequencies. In particular, the plurality ofmesh nodes 120 may use OFDM modulation as described in the 802.xx familyof standards developed by the Institute of Electrical and ElectronicEngineers (IEEE) and/or variations and evolutions of these standards(e.g., 802.11x, 802.15, 802.16x, etc.) to communicate via wirelesslinks.

For example, the plurality of mesh nodes 120 may operate in accordancewith the 802.16 family of standards developed by IEEE to provide forfixed, portable, and/or mobile broadband wireless access (BWA) networks(e.g., the IEEE std. 802.16, published 2004). The plurality of meshnodes 120 may also use direct sequence spread spectrum (DSSS) modulation(e.g., the IEEE std. 802.11b) and/or frequency hopping spread spectrum(FHSS) modulation (e.g., the IEEE std. 802.11). Although the aboveexamples are described above with respect to standards developed byIEEE, the methods and apparatus disclosed herein are readily applicableto many specifications and/or standards developed by other specialinterest groups and/or standard development organizations (e.g.,Wireless Fidelity (Wi-Fi) Alliance, Worldwide Interoperability forMicrowave Access (WiMAX) Forum, Infrared Data Association (IrDA), ThirdGeneration Partnership Project (3GPP), etc.). For example, the pluralityof mesh nodes 120 may also operate in accordance with other suitablewireless communication protocols that require very low power such asBluetooth®, Ultra Wideband (UWB), and/or radio frequency identification(RFID) to communicate via wireless links.

Alternatively, the plurality of mesh nodes 120 may communicate via wiredlinks (not shown). For example, the plurality of mesh nodes 120 may usea serial interface, a parallel interface, a small computer systeminterface (SCSI), an Ethernet interface, a universal serial bus (USB)interface, a high performance serial bus interface (e.g., IEEE 1394interface), and/or any other suitable type of wired interface tocommunicate.

In addition to the wireless mesh network 110, the wireless communicationsystem 100 may include other communication networks. In one example, thewireless communication system 100 may include a basic service set (BSS)network (not shown). One or more of the plurality of mesh nodes 120 maycommunicate with an access point (AP) associated with the BSS network.The BSS network may include one or more stations. For example, a stationassociated with the BSS network may be a wireless electronic device suchas a laptop computer, a handheld computer, a tablet computer, a cellulartelephone (e.g., a smart phone), a pager, an audio and/or video player(e.g., an MP3 player or a DVD player), a gaming device, a digitalcamera, a navigation device (e.g., a GPS device), a wireless peripheral(e.g., a headset, a keyboard, a mouse, etc.) and/or other suitablemobile or portable electronic devices. In another example, one or moreof the plurality of mesh nodes 120 may operate as an AP associated withthe BSS network (e.g., a mesh AP). Thus, the mesh AP may be a part ofthe wireless mesh network 110 and the BSS network.

The wireless communication system 100 may also include one or more radioaccess networks (RANs) such as a cellular radio network (not shown). TheRAN may include one or more base stations, and other radio componentsnecessary to provide wireless communication services. The base stationsmay operate in accordance with the applicable standard(s) for providingwireless communication services. That is, the base stations of the RANmay be configured to operate in accordance with one or more of severalwireless communication protocols.

In particular, the wireless communication protocols may be based onanalog, digital, and/or dual-mode communication system standards thatuse multiple access techniques such as frequency division multipleaccess (FDMA), time division multiple access (TDMA), and/or codedivision multiple access (CDMA). For example, the wireless communicationprotocols may include Global System for Mobile Communications (GSM),Wideband CDMA (W-CDMA), General Packet Radio Services (GPRS), EnhancedData GSM Environment (EDGE), Universal Mobile Telecommunications System(UMTS), High-Speed Downlink Packet Access (HSDPA), variations andevolutions of these standards, and/or other suitable wirelesscommunication standards.

Further, the wireless communication system 100 may include otherwireless personal area network (WPAN) devices, wireless local areanetwork (WLAN) devices, wireless metropolitan area network (WMAN)devices, and/or wireless wide area network (WWAN) devices such asnetwork interface devices and peripherals (e.g., network interface cards(NICs)), access points (APs), gateways, bridges, hubs, etc. to implementa cellular telephone system, a satellite system, a personalcommunication system (PCS), a two-way radio system, a one-way pagersystem, a two-way pager system, a personal computer (PC) system, apersonal data assistant (PDA) system, a personal computing accessory(PCA) system, and/or any other suitable communication system (notshown). Accordingly, the wireless communication system 100 may beimplemented to provide WPANs, WLANs, WMANs, WWANs, and/or other suitablewireless communication networks. Although certain examples have beendescribed above, the scope of coverage of this disclosure is not limitedthereto.

In the example of FIG. 2, a wireless mesh network 200 operating inaccordance with a multi-hop routing protocol may include a plurality ofmesh nodes 205, generally shown as 210, 220, 230, 240, 250, 260, and270. Although FIG. 2 depicts sixteen communication nodes, the wirelessmesh network 200 may include additional or fewer communication nodes.

A multi-hop routing protocol (e.g., Ad-Hoc On-Demand Distance Vector(AODV) routing protocol or Destination-Sequenced Distance Vector (DSDV)routing protocol) may identify a route across the wireless mesh network200 over which a packet may be forwarded from node to node. In oneexample, the mesh node 210 may be the source node (S), and the mesh node270 may be the destination node (D). The multi-hop routing protocol mayidentify a route 290 (e.g., shown by solid arrows) including multiplehops from the source node 210 to the destination node 270 (e.g., the hop294 between the mesh nodes 240 and 250).

The multi-hop routing protocol may be based on tables such that each ofthe plurality of mesh nodes 205 may include a routing table (e.g., oneshown as 300 in FIG. 3). As described in detail below, the routing tablemay include routing information such as destination node information,next hop information, metric information, and/or other suitable routinginformation.

Turning to FIG. 3, for example, the routing table 300 of the mesh node240 may include information indicating that the destination node is themesh node 270 via the route 290. The routing table 300 may also includeinformation indicating that the next hop from the mesh node 240 to themesh node 270 is the mesh node 250. Further, the routing table 300 mayinclude information indicative of a characteristic/condition of theroute 290 to compare to other routes. In particular, the metricinformation may indicate a hop count from one node to another. Forexample, the metric information may indicate that the mesh node 240 isthree hops from the mesh node 270. In addition or alternatively, themetric information may include information indicate an estimatetransmission count (ETX) and/or an end-to-end success rate.

In the example of FIG. 4, a wireless mesh network 400 operating inaccordance with a cooperative diversity protocol may include a pluralityof mesh nodes 405, generally shown as 410, 420, 430, 440, 450, 460, and470. Although FIG. 4 depicts sixteen communication nodes, the wirelessmesh network 400 may include additional or fewer communication nodes.

The cooperative diversity protocol may identify two or more of theplurality of mesh nodes 405 to transmit a packet simultaneously to adistant node (e.g., candidate nodes). In one example, the mesh nodes 450and 480 may be candidate nodes (C) of the mesh node 440, the mesh node460 may be a target node (T), and the mesh node 470 may be thedestination node (D). In particular, the target node 460 may be adistant neighbor node relative to the mesh node 440 en route to thedestination node 470. The candidate nodes 450 and 480 may be neighbornodes relatively closer to the mesh node 440 than the target node 460.Thus, the candidate nodes 450 and/or 480 may cooperate with the meshnode 440 to communicate with the target node 460. For example, the meshnode 440 may forward a packet to the candidate node 450 via the link 494and/or to the candidate node 480 via the link 495.

As described in detail below, the mesh node 440 may select the candidatenodes 450 and/or 480 to operate as cooperator node(s). When both themesh node 440 and the cooperator node(s) (e.g., selected candidatenode(s) 450 and/or 480) have the packet, the mesh node 440 and thecooperator node(s) may cooperate by transmitting the packetsimultaneously to the target node 460. For example, the mesh node 440and the candidate node 450 may simultaneously transmit a packet to thetarget node 460. In another example, the mesh node 440 and bothcandidate nodes 450 and 480 may simultaneously transmit a packet to thetarget node 460.

The mesh node 440 may include a cooperation table (e.g., one shown as500 in FIG. 5) to identify and select one or more cooperator nodes basedon the plurality of candidate nodes. In particular, the cooperationtable may include cooperation information such as neighbor nodeinformation, cooperator node information, metric information, and/orother suitable cooperation information.

Referring to FIG. 5, for example, the cooperation table 500 of the meshnode 440 may indicate that the mesh node 460 may be a target node forthe mesh node 440. The cooperation table 500 may also indicate acooperator node, if any, to the target node 460. Further, thecooperation table 500 may provide information indicative of acharacteristic/condition of each path to the target node 460 (i.e., withor without cooperation from a cooperator node).

In one example, the cooperation table 500 may provide informationindicative of link quality associated with cooperative diversity. Inparticular, the cooperation table 500 may indicate the link quality ofeach path to the target node 460. For example, the cooperation table 500may indicate that the link quality of the link 496 (e.g., from thecandidate node 450 to the target node 460) is fifteen decibels (15 dB),and the link quality of the link 497 (e.g., from the candidate node 480to the target node 460) is twenty dB (20 dB). The cooperation table 500may also indicate the link quality of a path from the mesh node 440 tothe target node 460. For example, the cooperation table 500 may indicatethat the link quality of the link 498 is ten dB (10 dB).

Based on the cooperation table 500, the mesh node 440 may select thecandidate node 480 as the cooperator node instead of the candidate node450 because of the link quality of the link 497 is better than the linkquality of the link 496. The mesh node 440 may forward a packet to thecooperator node 480 via the link 495. Accordingly, the mesh node 440 andthe cooperator node 480 may transmit the packet simultaneously to thetarget node 460.

In another example, the mesh node 440 may cooperate with both thecandidate nodes 450 and 480 to communicate with the target node 460(i.e., the mesh node 440 may select both candidate nodes 450 and 480 tooperate as cooperator nodes). Thus, the mesh node 440 may forward apacket to the cooperator node 450 via the link 494 and to the cooperatornode 480 via the link 495. The mesh node 440 and the cooperator nodes450 and 480 may transmit the packet simultaneously to the target node460.

As described above, a plurality of communication nodes may operate inaccordance with a multi-hop routing protocol to forward a packetsequentially from one communication node to another until thedestination node receives the packet. For example, a communication nodemay transmit a packet to a neighbor node (e.g., the next hop of amulti-hop route), which in turn, forwards the packet to another node.The multi-hop routing protocol may increase end-to-end range and/orreliability. However, the multi-hop routing protocol may be limited to aparticular range for each hop.

With a cooperative diversity protocol, two or more communication nodesmay transmit simultaneously (or concurrently) and independently to allowa relatively distant node to receive a transmission. For example, acommunication node may transmit a packet to a neighbor node (e.g., thenext hop of a multi-hop route). The communication node and the neighbornode may cooperate with each other to forward the packet to the distantnode. Thus, the cooperative diversity protocol may extend thetransmission range at a particular transmission power or vice versa.However, the cooperative diversity protocol may provide numerouscandidates for a particular communication node to cooperate with toreach the distant node.

Based on signal propagation, node topology, and/or othercondition/characteristic of a wireless communication network, either themulti-hop routing protocol or the cooperative diversity protocol may bemore effective. Accordingly, the methods and apparatus described hereinmay provide an integrated multi-hop routing and cooperative diversitysystem that may operate in accordance with a multi-hop routing protocoland a cooperative diversity protocol to identify an optimal path toroute a packet. The methods and apparatus described herein are notlimited in this regard.

In the example of FIG. 6, an integrated multi-hop routing andcooperative diversity system 600 may include a plurality ofcommunication nodes 605, generally shown as, 610, 620, 630, 640, 650,660, 670, and 680. Although FIG. 6 depicts sixteen communication nodes,the integrated multi-hop routing and cooperative diversity system 600may include additional or fewer communication nodes.

Turning to FIG. 7, a communication node 700 of the integrated multi-hoprouting and cooperative diversity system 600 (e.g., the communicationnode 640 of FIG. 6) may include a communication interface 710, a nodeidentifier 720, a node selector 730, a path selector 735, and a memory740. Although FIG. 7 depicts components of the communication node 700coupling to each other via a bus 750, these components may beoperatively coupled to each other via other suitable direct or indirectconnections (e.g., a point-to-point connection).

The communication interface 710 may include a receiver 712, atransmitter 714, and an antenna 716. The communication interface 710 mayreceive and/or transmit data via the receiver 712 and the transmitter714, respectively. The antenna 716 may include one or more directionalor omni-directional antennas such as dipole antennas, monopole antennas,patch antennas, loop antennas, microstrip antennas, and/or other typesof antennas suitable for transmission of radio frequency (RF) signals.Although FIG. 7 depicts a single antenna, the communication node 700 mayinclude additional antennas. For example, the communication node 700 mayinclude a plurality of antennas to implement amultiple-input-multiple-output (MIMO) system.

As described in detail below, the node identifier 720 may identify atarget node. In particular, the target node may be associated with apath from the communication node toward a destination node of amulti-hop route. The node selector 730 may select one or more neighbornodes (e.g., candidate node(s)) so that the communication node 700 andthe selected one or more neighbor nodes (e.g., cooperator node(s)) mayoperate cooperatively to communicate with the target node. The pathselector 735 may select a sub-path (e.g., either a multi-hop routingsub-path or a cooperative diversity sub-path) to route a packet from thecommunication node 700 toward the destination node.

The memory 740 may store a routing table 760 and a cooperation table770. The routing table 760 may include routing information such asdestination node information, next hop information, metric information,and/or other suitable routing information. The cooperation table 770 mayinclude cooperation information such as neighbor node information,cooperator node information, metric information, and/or other suitablecooperation information. Although the above example describes the memory740 storing tables, other suitable data structures (e.g., lists, arrays,etc.) may be used to store routing and cooperation information in thememory 740.

While the components shown in FIG. 7 are depicted as separate blockswithin the communication node 700, the functions performed by some ofthese blocks may be integrated within a single semiconductor circuit ormay be implemented using two or more separate integrated circuits. Forexample, although the receiver 712 and the transmitter 714 are depictedas separate blocks within the communication interface 710, the receiver712 may be integrated into the transmitter 714 (e.g., a transceiver). Inanother example, although the node identifier 720 and the node selector730 are depicted as separate blocks, the node identifier 720 and thenode selector 730 may be integrated into a single component.

To select dynamically a path to route a packet based on a multi-hoprouting protocol and a cooperative diversity protocol, the communicationnode 700 may include a protocol stack based on the Open SystemsInterconnection (OSI) Reference Model (e.g., the protocol stack 800 ofFIG. 8). Referring to FIG. 8, for example, the protocol stack 800 mayinclude an application layer 810, a transport layer 820, a multi-hoprouting layer 830, a media access address (MAC) layer 840, and aphysical (PHY) layer 850. Although FIG. 8 depicts a particular number ofprotocol layers, the protocol stack 800 may include additional or fewerprotocol layers.

The application layer 810 may enable applications to access networkservices. In particular, the application layer 810 may perform commonapplication services for application processes. For example, theapplication layer 710 may include protocols such as Hypertext TransferProtocol (HTTP), File Transfer Protocol (FTP), Telnet, Simple MailTransfer Protocol (STMP), Simple Network Management Protocol (SNMP),Network Time Protocol (NTP), Network File System (NFS), X.400, X.500,etc.

The transport layer 820 may establish sessions and ensure reliability ofdata flow. In particular, the transport layer 820 may providetransparent transfer of data between end users. For example, thetransport layer 820 may include protocols such as Net Basic Input/OutputSystem (BIOS) Extended User Interface (NetBEUI), Sequence PacketExchange (SPX), User Datagram Protocol, Transmission Control Protocol(TCP), etc.

In general, the multi-hop routing layer 830 (i.e., network layer) mayhandle link services, and addressing, routing, and error checkingfunctions. For example, the multi-hop routing layer 830 may includeprotocols such as NetBEUI, Internet Packet Exchange (IPX), InternetProtocol (IP), AODV, DSDV, etc. As described in detail below, themulti-hop routing layer 830 may operate to identify a target node forthe communication node 700 and determine whether to forward a packet tothe target node via a multi-hop routing sub-path or a cooperativediversity sub-path.

The MAC layer 840 (i.e., data link layer) may transfer data betweennetwork entities, and correct errors that may occur in the PHY layer850. For example, the MAC layer 840 may include protocols such asEthernet, Token Ring, Fiber Distributed Data Interface (FDDI),Point-to-Point Protocol (PPP), Frame Relay, High-Level Data Link Control(HDLC), Asynchronous Transfer Mode (ATM), X.25, Carrier Sense MultipleAccess (CSMA), CSMA with Collision Avoidance (CSMA/CA), CSMA withCollision Detection (CSMA/CD), etc.

The PHY layer 850 may establish and terminate a connection to acommunication medium. In particular, the PHY layer 850 may performservices requested by the MAC layer 840. For example, the PHY layer 850may include protocols such as RS-232, DSL, Integrated Services DigitalNetwork (ISDN), T1, OFDM, etc.

Although the above examples may describe particular protocols for theprotocol layers of the protocol stack 800, each protocol layer mayinclude other suitable protocols. For example, the MAC layer 840 and thePHY layer 850 may include other suitable wired or wireless protocols.

The protocol stack 800 may also include a cooperative diversity layer860. The cooperative diversity layer 860 may be operatively coupled tothe MAC layer 840 and independent of the multi-hop routing layer 830. Inone example, the cooperative diversity layer 860 may integrated with theMAC layer 840 and/or the PHY layer 850, and the multi-hop routing layer830 may be stacked above the MAC layer 840. As described in detailbelow, the multi-hop routing layer 830 may request a packet to be sentto a neighbor node of the communication node 600 (e.g., the next hop).The cooperation layer 860 may use the cooperation table 770 to determinethe cooperation, if any, required to reach the neighbor node selected bythe multi-hop routing layer 830.

By integrating multi-hop routing and cooperative diversity, themulti-hop routing layer 830 may identify a particular target for thecooperation layer 860, which may reduce the resource needed to searchfor cooperator node(s) to form a sub-path of a path from thecommunication node 700 toward the destination. In turn, the cooperationlayer 860 may provide a greater selection of paths for the multi-hoprouting layer 830.

While the components shown in FIG. 8 are depicted as separate blockswithin the protocol stack 800, the functions performed by some of theseprotocol layers may be integrated within a single protocol layer or maybe implemented using two or more separate protocol layers. For example,although the multi-hop routing layer 830 and the MAC layer 840 aredepicted as separate blocks within the protocol stack 800, the multi-hoprouting layer 830 may be integrated into the MAC layer 840 as long asthe cooperative diversity layer 860 is independent of the multi-hoprouting layer 830. In one example, the multi-hop routing layer 830 maybe integrated into an upper portion of the MAC layer 840 whereas thecooperative diversity layer 860 may be integrated into a lower portionof the MAC layer 840. The methods and apparatus described herein are notlimited in this regard.

Referring back to FIG. 6, each of the plurality of communication nodes605 may operate in accordance with a multi-hop routing protocol (e.g.,AODV, DSDV, etc.) to identify a route from a source node to adestination node. In one example, the communication node 610 may be asource node (S) and the communication node 870 may be a destination node(D). A multi-hop route from the source node 610 to the destination node670 may include links 691, 692, 693, 694, 696, and 699 (e.g., amulti-hop routing sub-path).

As noted above, the communication node 640 may determine that thecommunication node 650 is the next hop for the communication node 640toward the communication node 670. Accordingly, the communication node640 may update a corresponding routing table (e.g., the routing table760 of FIG. 9). In the example of FIG. 9, the routing table 760 mayindicate the link quality (e.g., signal strength) and/or other suitablemetric information of the link between the communication nodes 640 and650. Although FIG. 9 depicts one entry, the routing table 760 mayinclude additional entries.

Further, each of the plurality of communication nodes 605 may operate inaccordance with a multi-hop routing protocol to identify a target node(T) (e.g., a two-hop neighbor node). For example, the node identifier720 (e.g., via the multi-hop routing layer 830) may identify the targetnode for the communication node 700. In a unidirectional route, acommunication node may have one two-hop neighbor node. In one example,the communication node 660 may be a two-hop neighbor node of thecommunication node 640 (e.g., via a path through the communication node650 selected by the multi-hop routing layer 830). Alternatively, in abi-directional route, a communication node may have two two-hop neighbornodes.

To identify the target node, each of the plurality of communicationnodes 605 may transmit a broadcast message indicating a correspondingone-hop neighbor node. For example, the communication node 700 (e.g.,via the communication interface 710) may transmit the broadcast message.In one example, the communication node 650 may periodically transmit abroadcast message indicating that the communication node 660 is the nexthop for the communication node 650 toward the communication node 670(i.e., the communication node 660 is the corresponding one-hop neighbornode of the communication node 650). The communication node 640 mayreceive the broadcast message from the communication node 650 becausethe communication node 640 is a neighbor node of the communication node650.

In one example, the multi-hop routing layer 830 of the communicationnode 700 may provide the identity of the two-hop neighbor node (e.g.,the communication node 660 of FIG. 6) to the cooperative diversity layer860. The two-hop neighbor node may become the target node for thecooperative diversity layer 860, which attempts to create a link to thetarget node by cooperating with one or more neighbor nodes (i.e.,candidate nodes (C)).

The node selector 730 (e.g., via the cooperative diversity layer 860)may select one or more candidate nodes to operate as cooperator node(s)based on metric information to reach a target node. For example, thecooperative diversity layer 860 may identify one or more neighbor nodesassociated with a condition indicative of a strong communication linkwith the communication node 640 as candidate node(s) (e.g., a highsignal-to-noise ratio (SNR), a link that supports high bit rates, etc.).The cooperative diversity layer 860 may select one or more of thecandidate node(s) to operate as the cooperator node(s). In particular,the communication node 640 and the cooperator node(s) may operatecooperatively to communicate with the target node 660. Accordingly, thecooperative diversity layer 860 may add an entry associated with each ofthe selected cooperator node(s) to a corresponding cooperative diversitytable (e.g., the cooperative diversity table 770 of FIG. 10).

Turning to FIG. 10, for example, the cooperation table 770 may includeone or more entries to provide cooperation information such as neighbornode information, cooperator node information, metric information,and/or other suitable cooperation information. Although FIG. 10 depictsthree entries, the routing table 770 may include additional or fewerentries.

In one example, the entry 1010 may provide link quality informationassociated with the link 696 between the candidate node 650 and thetarget node 660 if the communication node 640 and the candidate node 650operate cooperatively to communicate with the target node 660. Inanother example, the entry 1020 may provide link quality informationassociated with the link 697 between the candidate node 680 and thetarget node 660 if the communication node 640 and the candidate node 680operate cooperatively to communicate with the target node 660. Thecooperation table 770 may also provide link quality informationassociated with a link without the assistance of a cooperator node. Forexample, the entry 1030 may provide link quality information associatedwith the link 698 between the communication node 640 and the target node660 (e.g., the communication node 640 directly communicating with thetarget node 660).

The communication node 640 may select the candidate node 680 to operateas a cooperator node because the cooperation table 770 may indicate thatcooperation with the candidate node 680 provides better link quality(e.g., a total of 30 dB with 20 dB from the link 697 and 10 dB from thelink 698) than either cooperation with the candidate node 650 or withoutcooperation (e.g., 25 dB and 10 dB, respectively). The communicationnode 640 may operate cooperatively with the cooperator node 680 tocommunicate with the target node 660. In one example, the communicationnode 640 may forward a packet to the cooperator node 680. Accordingly,the cooperator node 680 and the communication node 640 may transmit thepacket simultaneously to the target node 660 via the links 697 and 698,respectively. The packet may reach the target node 660 with a combinedsignal strength of thirty dB (e.g., 20 dB from the link 697 and 10 dBfrom the link 698). Thus, the packet may propagate from the source node610 to the destination node 670 via a multi-hop route including links691, 692, 693, and 699 as well as a link formed through cooperativediversity by combining links 697 and 698. Thus, the multi-hop routedescribed above may represent a hybrid route resulting from acombination of multi-hop routing and cooperative diversity.

At each hop, the path selector 735 (e.g., via the multi-hop routinglayer 830) may choose a sub-path (e.g., either the multi-hop routingsub-path or the cooperative diversity sub-path) to route the packet fromthe communication node 700 toward the destination node 670. As notedabove, the multi-hop routing layer 830 identified the multi-hop routingsub-path, which includes cooperation between the links 694 and 696. Thecooperative diversity layer 860 identified the cooperative diversitysub-path, which includes cooperation between the communication node 640and candidate node(s) 650 and/or 680.

FIG. 11 depicts one manner in which the example communication node 700of FIG. 7 may be configured to operate in a cooperative routing system.The example process 1100 of FIG. 11 may be implemented asmachine-accessible instructions utilizing any of many differentprogramming codes stored on any combination of machine-accessible mediasuch as a volatile or nonvolatile memory or other mass storage device(e.g., a floppy disk, a CD, and a DVD). For example, themachine-accessible instructions may be embodied in a machine-accessiblemedium such as a programmable gate array, an application specificintegrated circuit (ASIC), an erasable programmable read only memory(EPROM), a read only memory (ROM), a random access memory (RAM), amagnetic media, an optical media, and/or any other suitable type ofmedium.

Further, although a particular order of actions is illustrated in FIG.11, these actions may be performed in other temporal sequences. Again,the example process 1100 is merely provided and described in conjunctionwith the communication node 700 of FIG. 7 as an example of one way toconfigure a communication node to operate to provide the integratedmulti-hop routing and cooperative diversity system 800 of FIG. 8.

In the example of FIG. 11, the process 1100 may begin with thecommunication node 700 (e.g., via the node identifier 720 of FIG. 7 andthe multi-hop routing layer 830 of FIG. 8) identifying and selecting thebest next hop toward the destination (block 1110). For example, thecommunication node 700 may identify and select a neighbor nodeassociated with a link quality relative better than other neighbor nodesof the communication node 700. Accordingly, the communication node 700(e.g., via the multi-hop routing layer 830 of FIG. 8) may update therouting table 760 (block 1120). The communication node 700 (e.g., viathe multi-hop routing layer 830 of FIG. 8) may identify a target nodetoward the destination, which may be a two-hop neighbor on a selectedmulti-hop routing sub-path (block 1130).

The communication node 700 (e.g., via the cooperative diversity layer860 of FIG. 8) may select a candidate node to operate as a cooperatornode to communicate with the target node (block 1140). The communicationnode 700 (e.g., via cooperative diversity layer 860 of FIG. 8) maydetermine whether the candidate node may communicate with the targetnode (block 1150). If the communication node 700 may reach the targetnode via the candidate node, the communication node 700 (e.g., via thenode selector 730 of FIG. 7) may add an entry associated with thecandidate node to the cooperation table 770 (block 1160). In particular,the entry may indicate that the candidate node may operate as acooperator node. The entry may also provide metric informationassociated with the link between the cooperator node and the destinationnode. Accordingly, the communication node 700 (e.g., via the cooperationlayer 860 of FIG. 8) may notify the multi-hop routing layer 830 of a newcooperative diversity sub-path to the target node (block 1170). Controlmay return to the multi-hop routing layer 830 to block 1110. Themulti-hop routing layer 830 may determine whether to use the multi-hoprouting sub-path or the cooperative diversity sub-path as the next hoptoward the destination node. In one example, the multi-hop routing layer830 may choose to use the path with better metrics (e.g., a linkcondition/characteristic such as bit error rate, total powerconsumption, etc.).

Turning back to block 1150, if the communication node 700 cannot reachthe target node via the candidate node, the communication node 700 maydetermine whether additional candidate nodes are available (block 1180).For example, if the communication node 700 is unable to transmit apacket to the target node with cooperation from a candidate node, thecommunication node 700 may attempt to reach the target node via othercandidate nodes. If additional candidate nodes are available, controlmay return to block 1140. Otherwise if no additional candidate node isavailable, control may return to the multi-hop routing layer 830 atblock 1130.

While the methods and apparatus disclosed herein are described in FIG.11 to operate in a particular manner, the methods and apparatusdisclosed herein are readily applicable without certain blocks depictedin FIG. 11. In addition, while FIG. 11 depicts particular blocks, theactions performed by some of these blocks may be integrated within asingle block or may be implemented using two or more separate blocks.

Further, although the methods and apparatus disclosed herein aredescribed with respect to wireless mesh networks the methods andapparatus disclosed herein are readily applicable to many other types ofwireless communication networks. For example, the methods and apparatusdisclosed herein may be applied to WPANs, WLANs, WMANs, WWANs, and/orbroadband wireless access (BWA) networks. In one example, the methodsand apparatus disclosed herein may be applicable to access points and/orbase stations. The methods and apparatus described herein are notlimited in this regard.

FIG. 12 is a block diagram of an example processor system 2000 adaptedto implement the methods and apparatus disclosed herein. The processorsystem 2000 may be a desktop computer, a laptop computer, a handheldcomputer, a tablet computer, a PDA, a server, an Internet appliance,and/or any other type of computing device.

The processor system 2000 illustrated in FIG. 12 includes a chipset2010, which includes a memory controller 2012 and an input/output (I/O)controller 2014. The chipset 2010 may provide memory and I/O managementfunctions as well as a plurality of general purpose and/or specialpurpose registers, timers, etc. that are accessible or used by aprocessor 2020. The processor 2020 may be implemented using one or moreprocessors, WLAN components, WMAN components, WWAN components, and/orother suitable processing components. For example, the processor 2020may be implemented using one or more of the Intel® Pentium® technology,the Intel® Itanium® technology, the Intel® Centrino™ technology, theIntel® Xeon™ technology, and/or the Intel® XScale® technology. In thealternative, other processing technology may be used to implement theprocessor 2020. The processor 2020 may include a cache 2022, which maybe implemented using a first-level unified cache (L1), a second-levelunified cache (L2), a third-level unified cache (L3), and/or any othersuitable structures to store data.

The memory controller 2012 may perform functions that enable theprocessor 2020 to access and communicate with a main memory 2030including a volatile memory 2032 and a non-volatile memory 2034 via abus 2040. The volatile memory 2032 may be implemented by SynchronousDynamic Random Access Memory (SDRAM), Dynamic Random Access Memory(DRAM), RAMBUS Dynamic Random Access Memory (RDRAM), and/or any othertype of random access memory device. The non-volatile memory 2034 may beimplemented using flash memory, Read Only Memory (ROM), ElectricallyErasable Programmable Read Only Memory (EEPROM), and/or any otherdesired type of memory device.

The processor system 2000 may also include an interface circuit 2050that is coupled to the bus 2040. The interface circuit 2050 may beimplemented using any type of interface standard such as an Ethernetinterface, a universal serial bus (USB), a third generation input/output(3GIO) interface, and/or any other suitable type of interface.

One or more input devices 2060 may be connected to the interface circuit2050. The input device(s) 2060 permit an individual to enter data andcommands into the processor 2020. For example, the input device(s) 2060may be implemented by a keyboard, a mouse, a touch-sensitive display, atrack pad/ball, an isopoint, and/or a voice recognition system.

One or more output devices 2070 may also be connected to the interfacecircuit 2050. For example, the output device(s) 2070 may be implementedby display devices (e.g., a light emitting display (LED), a liquidcrystal display (LCD), a cathode ray tube (CRT) display, a printerand/or speakers). The interface circuit 2050 may include, among otherthings, a graphics driver card.

The processor system 2000 may also include one or more mass storagedevices 2080 to store software and data. Examples of such mass storagedevice(s) 2080 include floppy disks and drives, hard disk drives,compact disks and drives, and digital versatile disks (DVD) and drives.

The interface circuit 2050 may also include a communication device suchas a modem or a network interface card to facilitate exchange of datawith external computers via a network. The communication link betweenthe processor system 2000 and the network may be any type of networkconnection such as an Ethernet connection, a digital subscriber line(DSL), a telephone line, a cellular telephone system, a coaxial cable,etc.

Access to the input device(s) 2060, the output device(s) 2070, the massstorage device(s) 2080 and/or the network may be controlled by the I/Ocontroller 2014. In particular, the I/O controller 2014 may performfunctions that enable the processor 2020 to communicate with the inputdevice(s) 2060, the output device(s) 2070, the mass storage device(s)2080 and/or the network via the bus 2040 and the interface circuit 2050.

While the components shown in FIG. 12 are depicted as separate blockswithin the processor system 2000, the functions performed by some ofthese blocks may be integrated within a single semiconductor circuit ormay be implemented using two or more separate integrated circuits. Forexample, although the memory controller 2012 and the I/O controller 2014are depicted as separate blocks within the chipset 2010, the memorycontroller 2012 and the I/O controller 2014 may be integrated within asingle semiconductor circuit.

Although certain example methods, apparatus, and articles of manufacturehave been described herein, the scope of coverage of this disclosure isnot limited thereto. On the contrary, this disclosure covers allmethods, apparatus, and articles of manufacture fairly falling withinthe scope of the appended claims either literally or under the doctrineof equivalents. For example, although the above discloses examplesystems including, among other components, software or firmware executedon hardware, it should be noted that such systems are merelyillustrative and should not be considered as limiting. In particular, itis contemplated that any or all of the disclosed hardware, software,and/or firmware components could be embodied exclusively in hardware,exclusively in software, exclusively in firmware or in some combinationof hardware, software, and/or firmware.

1-30. (canceled)
 31. A method comprising: receiving, at a first node ofa wireless network, data for a first transmission to a second node ofthe wireless network over a first direct wireless link; andtransmitting, from the first node of the wireless network, the data fromthe first node to the second node substantially simultaneously with asecond transmission of the data from a third node of the wirelessnetwork to the second node over a second direct wireless link.
 32. Themethod of claim 31, wherein the wireless network is a third generationpartnership project (3GPP) wireless network.
 33. The method of claim 32,wherein the first transmission and the second transmission are downlinktransmissions of the 3GPP wireless network.
 34. The method of claim 31,further comprising receiving, at the first node, the data from a fourthnode of the wireless network.
 35. The method of claim 31, furthercomprising transmitting, by the first node, the data from the first nodeto the third node prior to the first transmission and the secondtransmission.
 36. The method of claim 31, further comprising controllinga timing of the first transmission so that the first transmission occurssubstantially simultaneously with the second transmission.
 37. Anapparatus comprising: a processor; and a receiver coupled with theprocessor, the receiver to: receive a first transmission of data from afirst node of a wireless network over a first direct wireless linkbetween the apparatus and the first node; and receive, substantiallysimultaneously with the reception of the first transmission, a secondtransmission of the data from a second node of the wireless network overa second direct wireless link between the apparatus and the second node.38. The apparatus of claim 37, wherein the wireless network is a thirdgeneration partnership project (3GPP) wireless network.
 39. Theapparatus of claim 38, wherein the first node or the second node are3GPP base stations.
 40. The apparatus of claim 37, wherein the receptionof the first transmission substantially simultaneously with thereception of the second transmission provides an improved receivedsignal quality over the reception of only the first transmission or thesecond transmission.
 41. One or more non-transitory computer readablemedia comprising instructions to, upon execution of the instructions bya processor of a base station of a wireless network, cause the basestation to: receive data for transmission to a receiving node of thewireless network over a first direct wireless link; facilitatetransmission of the data from a first transmission node of the wirelessnetwork to a receiving node of the wireless network over a first directwireless link; and facilitate transmission of the data from a secondtransmission node of the wireless network to the receiving node over asecond direct wireless link substantially simultaneously with thetransmission over the first direct wireless link.
 42. The one or morenon-transitory computer readable media of claim 41, wherein the wirelessnetwork is a third generation partnership project (3GPP) wirelessnetwork.
 43. The one or more non-transitory computer readable media ofclaim 41, further comprising instructions to transmit the data from thebase station to the first transmission node and the second transmissionnode prior to the transmission of the data from the first transmissionnode or the second transmission node to the receiving node.
 44. The oneor more non-transitory computer readable media of claim 41, furthercomprising instructions to control a timing of the transmission of thedata from the first transmission node and the second transmission nodeto the receiving node such that the data is transmitted from the firsttransmission node to the receiving node substantially simultaneouslywith the transmission of the data from the second transmission node tothe receiving node.
 45. The one or more non-transitory computer readablemedia of claim 41, wherein the first transmission node is the basestation.
 46. A system comprising: a first base station in a wirelessnetwork, the first base station to transmit data to a receiving node inthe wireless network in a first wireless transmission over a firstdirect wireless link between the first base station and the receivingnode; and a second base station in the wireless network, the second basestation to transmit the data to the receiving node in a second wirelesstransmission over a second direct wireless link between the second basestation and the receiving node substantially simultaneously with thefirst wireless transmission.
 47. The system of claim 46, wherein thewireless network is a third generation partnership project (3GPP)wireless network.
 48. The system of claim 46, wherein the first basestation is further to transmit the data to the second base station priorto the first wireless transmission and the second wireless transmission.49. The system of claim 46, wherein the first wireless transmission andthe second wireless transmission have an improved received signalquality at the receiving node compared to only the first wirelesstransmission or the second wireless transmission.
 50. The system ofclaim 46, wherein the first base station is further to alter a timing ofthe first wireless transmission so that the first wireless transmissionoccurs substantially simultaneously with the second wirelesstransmission.